Direct laser sintering of metal inks is a known technique for metallization of printed wiring. For example, U.S. Patent Application Publication 2008/0286488 describes a method of forming a conductive film based on depositing a non-conductive film on a surface of a substrate. The film contains a plurality of copper nanoparticles, and exposing at least a portion of the film to light makes the exposed portion conductive by photosintering or fusing the copper nanoparticles.